This application claims the priority of German patent 198 31 527, filed Jul. 14, 1998, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a hydraulic operating system for the brake and/or the clutch of a vehicle, particularly a motorcycle, having an operating element for acting upon a hydraulic cylinder, which is assigned to the brake and/or the clutch, and having a compensating tank for the hydraulic fluid.
The charging of such operating systems with hydraulic fluid takes place in many cases by way of the compensating tank of the hydraulic circulation system. As a rule, a return flow bore is also provided at this point so that the hydraulic fluid can flow unhindered from the compensating tank back to the operating cylinder. This arrangement results in the disadvantage that, during the charging--which, as a rule, takes place in a vacuum--air pockets may form in the pipe system.
In the case of known motorcycles, the compensating tank is part of the hand brake and clutch system on the motorcycle handle bar. This leads to additional disadvantages. Thus, the charging can take place only in a certain handle bar position or alignment of the compensating tank. Furthermore, the cover of the compensating tank must be unscrewed before the charging operation and must then be fastened again. Because of the vacuum filling, a large surface of the opened compensating tank must be sealed off by the filling device before the charging operation. On the whole, contaminations of the handle bar fittings by the hydraulic fluid must nevertheless be expected.
It is an object of the invention to provide an apparatus for charging an operating system of the above-mentioned type, in the case of which air pockets can be largely avoided and which can be handled without any problems.
According to the invention, this and other objects have been achieved by providing a hydraulic operating system for at least one of a brake and a clutch of a vehicle, comprising: a compensating tank containing hydraulic fluid; a hydraulic cylinder which is assigned to said at least one of a brake and a clutch, said hydraulic cylinder communicating with said compensating tank; a filler connection piece provided at the hydraulic cylinder for charging the hydraulic cylinder with hydraulic fluid; and an operating element for acting upon said hydraulic cylinder.
According to the invention, this and other objects have been achieved by providing a hydraulic operating system for one of a brake and a clutch of a vehicle, comprising: a hydraulic cylinder communicating with said one of a brake and a clutch; and a filler connection piece provided at the hydraulic cylinder for charging the hydraulic cylinder with hydraulic fluid.
According to the invention, this and other objects have been achieved by providing a method of making a hydraulic cylinder for one of a brake and a clutch of a vehicle which can be directly charged with hydraulic fluid, comprising: providing a filler connection piece at the hydraulic cylinder, said filler connection piece containing a return valve which can be opened by a filling device.
According to the invention, the charging therefore no longer takes place by way of the compensating tank but by way of a filler connection piece which is provided on the hydraulic cylinder assigned to the clutch or the brake.
Generally, as the result of the invention, the pipe system is charged at a point which is away from the return flow bore of the compensating tank. During the charging operation, the air still present in the pipes is therefore pushed to the bleed opening by the afterflowing hydraulic fluid. Air pockets therefore do not occur or occur far less.
The filler connection piece is expediently designed such that a filling device can be placed securely in a precise position and the filling opening can be opened up by it. For the first measure, the filler connection piece has a guide groove on its outer circumference; for the second measure, the filling opening is closed by a return valve which is opened up, for example, by a mandrel of the filling device.
Furthermore, it is advantageous to use, in addition to a return valve, a gland (i.e., seal) for closing the filling opening. As a result, it is ensured that, in the event of an unintentional lifting-off of the valve body, for example, in the case of vibrations, or in the event of a misuse, no hydraulic fluid can flow to the outside.
By way of the filler connection piece, the hydraulic circulation system can also be bled. For this purpose, a bleeder valve must only be screwed into the filling bore of the filler connection piece. If applicable, a gland (i.e., seal) must first be removed which is situated there.
In a particularly advantageous manner, the invention is suitable for motorcycles, in the case of which the compensating tank is part of the hand brake and clutch system fastened to the handle bar. Here, the filler connection piece is either screwed into the caliper or assigned to the clutch operating cylinder. In many cases, a bleed nipple is provided here anyhow. As a result of the invention, this bleed nipple is only replaced by the filler connection piece. A new constructive design of the concerned component, the caliper or the clutch operating cylinder is not necessary in these cases.
Furthermore, the invention permits a charging which is advantageous with respect to the assembly. Its position is independent of the compensating tank, and a contamination by emerging hydraulic fluid is largely prevented. The filling cross-section, which is relatively small in comparison to the compensating tank, permits an improvement of the system evacuation. Finally the charging quantity can be proportioned more precisely.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.